Fibers with absorbent particles adhered thereto, methods for their production and articles thereof

ABSTRACT

Composites where nonwoven fabrics having multicomponent synthetic fibers with adhered particles thereon are disclosed. The multicomponent fibers have at least one polymer component with a melting point below that of the other components, and the average apparent particle diameter is less than the average apparent fiber diameter. Methods of making the disclosed composites are also disclosed.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication No. 62/936,067, filed Nov. 15, 2019, which is incorporatedby reference herein in its entirety.

ACKNOWLEDGMENT OF GOVERNMENT FUNDING

This invention was made with government support under grant numberFA8750-14-D-0003 awarded by the U.S. Air Force Research Laboratory. Thegovernment has certain rights in the invention.

BACKGROUND

Fabrics containing particles that can absorb compounds or microbes havemany desirable uses. For example, such fabrics can be used for airfiltration or for protective clothing. Examples of protective clothingwith incorporated particles are combat uniforms for war theaters wherechemical warfare is a potential threat. Such uniforms need to becomfortable while offering sufficient protection; this meaning that theyneed to be light, drapable and breathable while offering the mechanicalproperties needed for this demanding environment in addition toinhibiting the chemical threat from being absorbed by the skin.

Currently uniforms exist that include an outer fabric, an inner fabric,and a core composite where a fabric is coated with a mixture of a binderand activated carbon particles. Activated carbon particles havelimitations for this application and the use of a binder binds asignificant percentage of the particles' surface, therefore reducing thecapacity of the particles to absorb compounds.

Fabrics containing particles that can release compounds have also manydesirable uses. For example, they can be used to release a fragrance orhealth beneficial compound into a stream of air.

Methods to attach particles onto a fabric without using a binder havebeen described. U.S. Pat. No. 6,024,813 describes blending absorbentparticles (e.g. activated carbon or zeolites) with bicomponent fibersthat typically have sheath:core cross sections. In this approach, thesheaths of the bicomponent fibers were heat activated and adhered to theoutside of the particles. In this approach, the particles were typicallysignificantly larger than the diameter of the fibers, resulting insignificant tangling where multiple fibers were connected together bythe particle, locking it in place. U.S. Pat. No. 5,786,059 describes asimilar approach of using sheath:core bicomponent fibers to lock largeraerogel particles in place to form composite fabrics.

A disadvantage of these approaches is that they require relatively largeparticles, therefore limiting the surface exposed to the outsideenvironment. This typically reduces the absorption capacity by weight ofthe absorbent particles.

There is thus a need for fibers and textile composites or fabrics thathave greater absorption capacity and are breathable. The composites,fibers, and methods disclosed herein address these and other needs.

SUMMARY

In accordance with the purposes of the disclosed materials and methods,as embodied and broadly described herein, the disclosed subject matter,in one aspect, relates to compositions and methods of using thecompositions. In specific aspects, the disclosed subject matter relatesto multicomponent synthetic fibers decorated with particles, wherein theparticles are smaller than the fiber diameter, and wherein the particlesare adhered to the fibers. Composites where nonwoven fabrics of suchfibers with adhered particles are also disclosed. In some examples, thencomposites have a majority (greater than about 75%) of the particlesadhered to only one fiber are also disclosed. Further, composites wherethe web porosity is at least about 90% are disclosed. Methods of makingthe disclosed composites are also disclosed.

Additional advantages will be set forth in part in the description thatfollows, and in part will be obvious from the description, or may belearned by practice of the aspects described below. The advantagesdescribed below will be realized and attained by means of the elementsand combinations particularly pointed out in the appended claims. It isto be understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof:

FIG. 1 is an example of a process to bring the hot particles in contactwith the nonwoven comprising multi-component fiber nonwoven.

FIG. 2 is a picture taken at 500× of PP/PE Island-in-the-Sea filamentswith MOF particles.

FIG. 3 is a picture taken at 500× of CoPET/PET Sheath:Core bicomponentfibers coated with MOF particles.

FIG. 4 is a picture taken at 250× of CoPET/PET Sheath:Core bicomponentfibers coated with MOF particles.

FIG. 5 is a picture taken at 250× of PE/PET Sheath:Core bicomponentfibers from highloft nonwoven coated with MOF particles.

FIG. 6 is a picture of the system used to coat Sample 5.

FIG. 7 is a picture taken at 250× of PE/PET Sheath:Core bicomponentfibers from highloft nonwoven coated with MOF particles by processingthe web in a bed of hot particles.

FIG. 8 is a picture taken at 300× of PE/PET Sheath:Core bicomponentfibers from high loft nonwoven coated with MOF particles byincorporating the particles into the nonwoven using vibrations, thenactivating the sheath of the fibers by exposure in an oven at 170° C.and followed by removal of the particles that had not adhered.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the inventions are shown. Preferred embodiments of theinvention may be described, but this invention may, however, be embodiedin many different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Theembodiments of the invention are not to be interpreted in any way aslimiting the invention.

Many modifications and other embodiments of the invention set forthherein will come to mind to one skilled in the art to which thisinvention pertains having the benefit of the teachings presented in thedescriptions herein and the associated drawings. Therefore, it is to beunderstood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.

Also, throughout this specification, various publications arereferenced. The disclosures of these publications in their entiretiesare hereby incorporated by reference into this application in order tomore fully describe the state of the art to which the disclosed matterpertains. The references disclosed are also individually andspecifically incorporated by reference herein for the material containedin them that is discussed in the sentence in which the reference isrelied upon.

Definitions

In this specification and in the claims that follow, reference will bemade to a number of terms, which shall be defined to have the followingmeanings:

Throughout the description and claims of this specification the word“comprise” and other forms of the word, such as “comprising” and“comprises,” means including but not limited to, and is not intended toexclude, for example, other additives, components, integers, or steps.

As used in the description and claims, the singular forms “a”, “an”, and“the” include plural referents unless the context clearly indicatesotherwise. For example, reference to “a fiber” includes a plurality ofsuch fibers.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed. The upper and lower limits of thesesmaller ranges may independently be included in the smaller ranges, andare also encompassed, subject to any specifically excluded limit in thestated range. Where the stated range includes one or both of the limits,ranges excluding either or both of those included limits are alsoincluded.

The term “fiber” herein is intended to include staple fibers as well ascontinuous filaments.

As used herein, a “nonwoven fabric” means a fabric having a structure ofindividual fibers or filaments that are interlaid but not necessarily inan identifiable manner as with knitted or woven fabrics.

As used herein, the term “adhered” is meant to describe a closeproximate association between different materials that is primarilyattributed to chemical forces, e.g., electrostatic, hydrogen, covalent,ionic, van der Waals bonding, or physical attachment between thematerials. An adhered particle, as described herein, is not associatedwith a fiber primarily because of physical entrapment by multiplefibers, as can be visually confirmed by microscopy, but rather byadhesive forces or physical attachment between the particle and a singlefiber.

Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation. Allterms, including technical and scientific terms, as used herein, havethe same meaning as commonly understood by one of ordinary skill in theart to which this invention belongs unless a term has been otherwisedefined. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningas commonly understood by a person having ordinary skill in the art towhich this invention belongs. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and the present disclosure. Suchcommonly used terms will not be interpreted in an idealized or overlyformal sense unless the disclosure herein expressly so definesotherwise.

Composites

Disclosed herein is a composite or nonwoven fabric that comprisessynthetic fibers with particles adhered to the fibers. The composite cancomprise multicomponent synthetic fibers, those fibers having one orseveral exposed surfaces of a component that melts at a lowertemperature than other component(s) of the fibers. The composite alsocomprises at least one type of active particles having apparentdiameters that are mostly smaller than the fiber diameters, theparticles being adhered to the fibers by direct adhesion to polymerforming an exposed part or parts of the fibers having the lower meltingpoint. The particle is adhered to the part of the fibers with the lowmelting temperature by heating the particles above the melting point ofthe low melting point component of the fibers, bringing those particlesin contact with the fabric, and subsequently cooling this fabric underthe melting point of any of its constituents. The results being anonwoven composite with several of the multicomponent fibers beingdecorated with particles adhered to them.

FIG. 1 illustrates an exemplary method for bringing particles intocontact with a fabric, e.g., a nonwoven. Another approach could includepre-heating the fabric prior to bringing it in contact with theparticles, preheating the particles prior to bringing them in contactwith the fabric, or pre-heating the particles and pre-heating the fabricbefore bringing them in contact with one another. Another approach couldinclude loading the fabric with particles, heating this composite, andthen removing the particles that have not adhered to the fiber. Further,at any step of the process the mixture of the fabric, fibers, andparticles can be vibrated to aid distribution of the particles. In anyof these methods care should be taken to maintain the integrity of thefibers while making a significant share of its surface tacky or adhesivein order to capture and retain a large quantity of the particles andachieving a good coverage.

Fibers

The fibers for use herein are synthetic multicomponent fibers. Suchfibers have two or more different polymer components where at least onepolymer is primarily exposed to the environment (external). Themulticomponent fibers can be bicomponent, tricomponent, or have four ormore components. The multicomponent fibers can have various differentconfigurations. For example, the multicomponent fiber can be sheath:core(concentric sheath:core or eccentric sheath:core), island-in-the-sea,side-by-side (50/50 or unequal side-by-side), segmented pie, or tippedtrilobal type fiber. For the sheath:core and other configurations thecross section is not limited to be round; options include trilobal,ribbon-shaped, oval, and others known in the art. Generally, a crosssection that provide a higher surface by gram of fiber may be moredesirable for some applications. The multicomponent fiber should have asignificant amount of its surface comprised of a polymer that can beheat activated to adhere to the particles.

The synthetic multicomponent fibers can be from about 5 to about 100microns in diameter. In certain examples, the diameter of themulticomponent fibers is from about 5 to about 10 microns, from about 10to about 20 microns, from about 20 to about 50 microns, from about 50 toabout 100 microns, from about 5 to about 10 microns, from about 5 toabout 20 microns, from about 5 to about 30 microns, from about 5 toabout 50 microns, from about 5 to about 100 microns, from about 10 toabout 30 microns, from about 30 to about 50 microns, or from about 50 toabout 100 microns. In specific examples, the multicomponent fibers arefrom about 15 to about 30 microns. The length of the multicomponentfibers need not be limited and can be a continuous fiber or a cut orstaple fiber.

In the synthetic multicomponent fibers, at least one of the polymercomponents on an exposed surface of the fiber has a melting point thatis at least 20° C. lower than any other components (polymers) of thefiber. In some examples, at least one of the polymer components on anexposed surface of the fiber has a melting point that is at least 30°C., 40° C., 50° C., or more lower than any other components (polymers)of the fiber. In some examples, the difference between the meltingpoints of at least two polymers in the fiber can be 20° C. or more,e.g., a 30° C., 40° C., 50° C. or greater than 50° C. difference.Melting point is defined herein as the peak temperature achieved when apolymer formulation melts as measured by differential scanningcalorimetry or DSC.

In certain examples, the multicomponent fiber comprises thermoplasticpolymers. In certain examples, the polymer components can comprise athermoplastic polymer selected from the group consisting of nylon 6,nylon 6/6, nylon 6/10, nylon 6/11, nylon 6/12, nylon 11, nylon 12,polyolefins such as polypropylene or polyethylene, polyesters,polyamides, co-polyesters, copolyetherester elastomers, polyacrylates,thermoplastic liquid crystalline polymers, and others.

An example of suitable multicomponent fiber is the sheath:corebicomponent fibers where the core comprises a polymer formulation havinga significantly higher melting point temperature polymer formulationthan the sheath. For example, this could be a bicomponent fiber having acore made from polyester (PET) and a sheath made from lower meltingpoint co-polyester (Co-PET) or even polyethylene. Another example wouldbe a bicomponent fibers made from a polypropylene core and apolyethylene sheath.

In other specific examples, the multicomponent fibers can be anisland-in-the-sea fiber having from about 2 to about 100 islands(internal components). In certain embodiments, the multi-component fibercan have from about 30 to about 40 islands. In other embodiments, themulti-component fiber can have from about 2 to about 100 islands, fromabout 10 to about 80 islands, from about 20 to about 60 islands, fromabout 30 to about 50 islands, from about 2 to about 10 islands, or fromabout 5 to about 30 islands. The sea component can be the polymer thathas a melting point lower than that of the polymer used to make theislands. For example, islands can be made from polyester (PET) and thesea can be made from lower melting point co-polyester (Co-PET) or evenpolyethylene or vice versa. Another example would be a bicomponentfibers made from a polypropylene islands and a polyethylene sea or viceversa.

Those are not restrictive examples and many other combinations arepossible, as long as they provide an exposed part of the fiber having alower melting temperature that can be heat activated than the othercomponents of the fiber.

The multi-component fibers can form the complete nonwoven or they can beblended with other fibers selected for their properties (e.g. largediameter fibers to provide resilience).

Nonwovens

The nonwovens useful herein can be made by different methods as long asthey comprise multicomponent fibers as described herein. These includespunbonds, carded webs, airlaid webs or wetlaid webs that can bethermally bonded by point bonding or thru-air bonding, or they can beneedled or, they can be hydro-entangled or they can be stabilized by anycombination of these methods. In a specific example is an opened webthat is easily penetrated by the particles prior to bonding. Examples ofsuitable webs are carded webs comprising a majority of multicomponentfibers that are through-air bonded, or spunbond made from self-crimpedfilaments that are thru-air bonded or point bond using a bonding patternthat optimizes loft (e.g. using a quilted bonding pattern). A way todescribe the well-opened structure of the preferred nonwoven is by itsweb porosity. Particularly suitable nonwoven used for the disclosedcomposites would have a web porosity above about 90%, e.g., above about92%, above about 95%, or above about 99%.

Web porosity W_(p) is defined as the % of a nonwoven volume not occupiedby the fibers or:

W _(p)=100*[1−(WD/FD)]

where WD is the density of the web in grams per cubic centimeter and FDis the fiber density expressed in grams per cubic centimeter.

WD is calculated from the basis weight BW expressed as grams per squaremeter and the thickness T₁ of the fabric expressed in mm as measuredunder a load of 0.41 KPa

WD=BW/(T ₁×10³)

FD for a bicomponent fiber can be calculated from the weight faction ofeach polymer (F_(x)) and the solid density of the polymer PD_(x)expressed in grams per cubic centimeter. For a bicomponent fibercomprised of polymer a and b, FD can be calculated as follow:

FD=(F _(a)×PD_(a))+(F _(b)×PD_(b))

Particles

In the disclosed composites, the relative size of the particles to thecross-sectional dimension of the fibers to which they are attached is asignificant parameter. Small particles offer more surface per gram ofparticles than larger ones. Also, the composite should contain a maximumload of particles, and as much of the surface of the fiber should becovered with the particles as possible. Thus, without wishing to bebound by theory, it is believed that more than about two thirds (66%) ofthe particles attached to the fibers should have an average apparentdiameter that is equal or smaller than about 100% the average apparentdiameter of the fiber, and preferably smaller than about 75% the averageapparent diameter of the fiber, and preferably smaller than about 50%the average apparent diameter of the fiber, even more preferably smallerthan about 33% the apparent diameter of the fiber and finally, morepreferably smaller than about 25% the apparent diameter of the fiber.

Average apparent diameter of the particle is the diameter of a smallestsphere that can contain entirely the particle. When smaller particlesagglomerate into larger ones, the agglomerate is considered a “particle”as used herein.

Average apparent diameter of the fiber is the average width of thefibers as measured at random for several fibers with a microscope. Thisapplies to non-round fibers where the standard deviation may be greateras the orientation of the fiber change.

A result of having a majority of the particles smaller than the fiberdiameter is that most of the particles are attached to only one fiber ata time, e.g., more than about 75%, 85%, or 95% of the particles can beattached to only one fiber at a time. This is a difference with priormethods and reflects the high particle surface to fiber surface ratiofor the disclosed composites.

Another aspect is the loading of particles onto the fibers and into thecomposite. The disclosed composites can have at least about 10% of thecomposite weight made-up of the active particles, preferably at leastabout 20%, most preferably at least about 30%, most preferably at leastabout 40%, and most preferably at least about 50%.

The particles that can be used herein can have an average diameter offrom about 0.1 to about 100 microns, from about 5 to about 10 microns,from about 10 to about 20 microns, from about 20 to about 30 microns,from about 30 to about 50 microns, from about 50 to about 100 microns,from about 0.1 to about 1 microns, from about 0.1 to about 5 microns,from about 0.1 to about 15 microns, from about 0.1 to about 50 microns,from about 1 to about 100 microns, from about 1 to about 15 microns,from about 15 to about 50 microns, or from about 50 to about 100microns.

In specific examples, the particles can be absorbent or reactiveparticles. For example, the particles can be carbon, zeolites, fumedsilica, alumina, titania, zirconia, clay, zeolitic imidazole framework(ZIF), polyoxymetalates, or metal organic frameworks (MOFs). MOFs arecrystalline inorganic materials, examples of which include UiO-66,UiO-66-NH₂, ZIF-8, or ZIF-7. While individually very small, MOFsaggregate to particles within suitable size ranges disclosed herein.

EXAMPLES

The following examples are set forth below to illustrate the methods andresults according to the disclosed subject matter. These examples arenot intended to be inclusive of all aspects of the subject matterdisclosed herein, but rather to illustrate representative methods andresults. These examples are not intended to exclude equivalents andvariations of the present invention, which are apparent to one skilledin the art.

General Methods

For Examples 1 to 4, MOFs were put in a beaker that was immersed in aheated oil bath. The oil was heated and the temperature of the powderwas raised above 130° C. as measured with a thermocouple inserted in thepowder. A powder temperature of from about 130° C. to about 140° C. wasreached. A strip of cut fabric was dipped into the heated powder withone side facing down and moved slowly. Then the fabric was dipped againwith the other side facing down. After that, the fabric was shaken toremove loosely attached particles. In a few instances, a jet of airprovided by a compressed air canister was used to remove looseparticles.

Example 1

A spunbond made from Island-in-the-Sea filaments having 37 islands madefrom polypropylene and a sheath of polyethylene was used in the generalmethod. The picture of the resulting fiber taken with a Keyence digitalmicroscope VHX-950F is found in FIG. 2. This figure shows a partialcoverage of the filaments with particles.

Example 2

The fabric used was made from sheath:core bicomponent fibers having asheath made from low melting point co-polyester and a core made fromhigher melting point polyester. This fabric was made by carding thefabric and through-air bonding while pressed between two metallic meshbelts. It had a nominal basis weight of 0.5 osy or 17 gsm (gram persquare meter). This fabric was used in the general method and thepicture of the resulting fibers taken with a Keyence microscope is foundin FIG. 3.

Example 3

The fabric used was made from sheath:core bicomponent fibers having asheath made from low melting point co-polyester and a core made fromhigher melting point polyester. This fabric was made by carding thefabric and through-air bonding while pressed between two metallic meshbelts. The basis weight was 0.8 osy or about 27 gsm. FIG. 4 is thepicture taken with the microscope of the resulting fibers. It shows verygood coverage of the fibers by the MOF particles.

Example 4

A fabric of a high loft nonwoven made by carding a web from bicomponentsheath:core fibers having a sheath made of polyethylene and a core ofpolyester was used in the general method. This web was through-airbonded without compression; therefore, it had a high bulk and couldeasily be penetrated by the MOF particles during the coating process.This web had a basis weight of approximately 76 gsm. FIG. 5 is amicroscopy picture of the coated fibers and illustrates the level ofcoverage achieved.

Example 5

For this example, the fabric was coated using an apparatus thatcomprises a V-shaped well immersed in a bath of heated oil (see FIG. 6).This well contained the heated MOF particles (typically the volume ofparticles in the well was from about 1 to about 2 liters of particles).A fabric having a width of from about 250 mm to about 275 mm wasunwinded from a mandrel and slowly passed into the bed of heated powderparticles before being winded on a mandrel on the opposite side. Whilethe fabric was immersed into the bed of hot particles, those werepressed against the fabric with the help of a metallic spoon to helpthem to penetrate into the fabric pore (This was done to simulate whatnip rolls could do in a larger scale process). This was done twice withdifferent sides of the fabric facing toward the bottom of the well. Theoil temperature, the residence time, and the amount of work performed topress the hot powder into the pores of the fabric could be varieddepending on the desired product or preference. At the end, the excesspowder that had not adhered to the filaments was removed by shaking thefabric and blowing it with compressed air.

The fabric used for this example was a sample of B4302G nonwovensmanufactured by Berry Global. It is a high loft through-air bondedcarded nonwoven made bicomponent fibers having a sheath made ofpolyethylene and a core of polyester (A 50:50 ratio of PE and PET wasassumed). The oil temperature was controlled at 200° C. and theresidence time of the fabric in contact with the hot particles was atleast 90 seconds. FIG. 7 shows one side of this sample after coatingwith MOF particles. Very little shrinkage of the fabric was observedduring the coating process. Large coated pieces of the fabric wereweighted after the excess powder that was not attached to the fibers wasremoved by shaking and blowing with compressed air. For a fabric havinga basis weight of about 60 gsm, a gain in basis weight of about 72 gsmor a gain in weight of about 120% was observed.

Example 6

In this example MOF particles were poured into a metallic deep pan and apneumatic vibrator (Vibco model VS-130) was attached to the wall of thepan. The fabric used for this example was B4302G made by Berry Global.This carded and through-air bonded fabric is made from sheath:corebicomponent fibers where the sheath is made of polyethylene and the coreis made of polyester. A piece of that fabric was put in the pan andcovered with MOF particles while the pan was vibrated with highintensity. The energy delivered by the vibration helped the particlespenetrate into the fabric structure. This piece of fabric loaded withMOF particles was then deposited onto a non-stick cookie sheet andcovered with a fluoropolymer coated non-stick fabric. This pan was thenheated in an air-circulated oven for 15 minutes at about 170° C. Afterbeing retrieved and while still hot, the loaded sample on the non-stickpan and covered by the non-stick fabric was gently compressed with arolling pin. The purpose of the latter was to help getting the MOFparticles embedded into the polymer forming the sheath of the fibers.The particles that were not adhered to the fibers were shaken off andblown away using compressed air. The results were that the sample offabric that had an original basis weight of 64 gsm, was measured at 124gsm after this operation; therefore, it had gained about 60 gsm of MOFparticles. This is a weight gain of about 94%. This sample is shown inFIG. 8.

Other advantages which are obvious and which are inherent to theinvention will be evident to one skilled in the art. It will beunderstood that certain features and sub-combinations are of utility andmay be employed without reference to other features andsub-combinations. This is contemplated by and is within the scope of theclaims. Since many possible embodiments may be made of the inventionwithout departing from the scope thereof, it is to be understood thatall matter herein set forth or shown in the accompanying drawings is tobe interpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A composite, comprising: multicomponent syntheticfibers, wherein the fibers comprise at least one exposed polymer andparticles adhered to the exposed polymer, wherein that exposed polymerhas a lower melting point than other components of the multicomponentfibers and, wherein at least about 66% of the adhered particles have anapparent diameter that is less than the average apparent diameter of themulti-component fibers.
 2. The composite of claim 1, wherein at leastabout 75% of the particles have adhered to the surface of only one ofthe multicomponent fibers.
 3. The composite of claim 1, wherein theadhered particles are at least about 10 wt. % of the composite weight.4. The composite of claim 1, wherein the adhered particles are at leastabout 20 wt. % of the composite.
 5. The composite of claim 1, whereinthe exposed polymer has a melting point at least about 20° C. lower thanother constituents of the multicomponent fibers.
 6. The composite ofclaim 1, where the particles are metal organic frameworks.
 7. Thecomposite of claim 1, where the multicomponent fibers are sheath:core,or island-in-the-sea, side-by-side, segmented pie, or tipped trilobaltype fibers.
 8. The composite of claim 1, wherein at least about 75% ofthe adhered particles have an apparent diameter that is less than theaverage apparent diameter of the multicomponent fibers.
 9. The compositeof claim 1, wherein at least about 90% of the adhered particles have anapparent diameter that is less than the average apparent diameter of thefibers.
 10. The composite of claim 1, wherein the adhered particles havean average apparent diameter that is about 75% smaller than the averageapparent diameter of the fibers.
 11. The composite of claim 1, whereinthe adhered particles have an average apparent diameter that is about50% smaller than the average apparent diameter of the fibers.
 12. Thecomposite of claim 1, wherein the adhered particles have an averageapparent diameter that is about 25% smaller than the average apparentdiameter of the fibers.
 13. The composite of claim 1, wherein themulticomponent fibers are in a nonwoven fabric.
 14. The composite ofclaim 13, wherein the nonwoven fabric is a spunbond, carded web, airlaidweb, or wetlaid web.
 15. The composite of claim 14, wherein the nonwovenfabric is bonded by thermal point bonding or thru-air thermal bonding,needled entangled, hydro-entangled.
 16. The composite of claim 14,wherein the nonwoven fabric has a web porosity above about 90%.
 17. Amethod of forming a composite, comprising: a. heating multicomponentsynthetic fibers, wherein the fibers comprise at least one exposedpolymer having a lower melting point that other components of themulticomponent fibers, to a temperature where the at least one exposedpolymer is molten; b. contacting the heated multicomponent syntheticfibers with particles, such that the particles adhere to the exposed,molten polymer; and c. cooling or allowing to cool the fibers withparticles adhered thereto. wherein at least about 66% of the adheredparticles have an apparent diameter that is less than the averageapparent diameter of the multi-component fibers.
 18. An article ofclothing comprising the composite of claim 1.